| Hypericum iwatelittorale | |
|---|---|
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| Holotype ofHypericum iwatelittorale | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Hypericaceae |
| Genus: | Hypericum |
| Series: | Hypericumser. Hypericum |
| Species: | H. iwatelittorale |
| Binomial name | |
| Hypericum iwatelittorale | |
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| Approximate location of thetype locality ofH. iwatelittorale inIwate Prefecture[1][2] | |
Hypericum iwatelittorale, originally styledHypericum iwate-littorale, is aspecies offlowering plant of the St John's wortfamily (Hypericaceae). Named for itshabitat in the coastal regions of theIwate Prefecture in Japan, the species is a smallperennial herb with many small star-shaped flowers of bright yellowpetals. It grows upright, with oval to elliptical leaves that are papery in texture and have an array ofglands. Each flower has dozens ofstamens, and the seeds are dark brown.
Described in 1937 by Japanese botanistHideo Koidzumi,Hypericum iwatelittorale has at times been considered asynonym ofH. pseudopetiolatum. However, it was accepted as avalid species in 2003 by English botanistNorman Robson. Robson placed the species into thetype section ofHypericum, and noted its similarities toH. tosaense. While several conservation surveys have included the species, each classified it asdata deficient and gave no assessment as to its status.
Hypericum iwatelittorale is aperennial herb that grows upright to a height of 25–32 centimeters (9.8–12.6 inches). The leaves on its lateral branches havepetiolules, or leaflet stalks, which have a shape between that of an ellipse and a blunted lance. The flowers are 0.9–1.0 cm (0.35–0.39 in) wide, with five yellow petals each. The leaf-likesepals that support the flower are 0.3–0.4 cm (0.12–0.16 in) long and are pointed, with few or noglands on their edges.[3]
The stems grow alone or in small groups, and have branches on their upper parts. They have two visible lines that run laterally and have black point-shaped glands. Theinternodes, or length of stem between leafnodes, are usually longer than the leaves themselves. The leaves are directly attached to the main stem, or have a shortleaf stalk when attached to the lateral branches. The leaf blade is 1.2–1.4 cm (0.47–0.55 in) long by 0.5–0.8 cm (0.20–0.31 in) wide, and is an oval to stretched-ellipse shape. The blades are a paler color on the undersides and have a papery texture. The leaf tip is rounded, the edges are smooth, and the base is blunt to rounded. There are dense, pale, point-shaped glands on the surface of the leaves, and black or reddish glands around the edges.[4]
Eachinflorescence, or flower cluster, has up to thirty flowers from as many as three primarynodes and four lower nodes. The cluster is in the shape of acorymb, with shortpedicels (connections between the flower and stem) and smallbracts (specialized leaves) that are lance-shaped. The flowers are 0.9–1.0 cm (0.35–0.39 in) wide and may be star-shaped. There are fivesepals of roughly the same size: 0.3–0.4 cm (0.12–0.16 in) long and 0.1–0.2 cm (0.039–0.079 in) wide. These sepals are pointed and lance-shaped, with pale glands on their surface and few or no black glands on their edges. Each flower has five bright yellowpetals that are 0.6–0.9 cm (0.24–0.35 in) long and have pale glands on their surface and very few black glands on their edges. There are around fiftystamens per flower, the longest of which is roughly 0.7 cm (0.28 in) long. Theseed capsules are roughly oval-shaped, with oil valves that run longitudinally. The seeds are dark brown, 0.12 cm (0.047 in) long, and arecylindric in shape.[4]
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| Cladogram showing the relationships between species of seriesHypericum[5] |
The species was first collected in 1934 byHideo Koidzumi, a Japanese botanist,[2] and wasoriginally described asHypericum iwate-littorale in theJournal of Plants of Iwateken in 1937.[6]Arika Kimura later doubted thevalidity of the species, and placed it as a synonym ofH. pseudopetiolatum insubsectionErecta. In 2003, as a part of hismonograph of the genusHypericum,Norman Robson restored it to the status ofvalid species and standardized its name asHypericum iwatelittorale. He also placed the species inseriesHypericum (thetype series of the typesectionHypericum) because of its raised stem lines with gland dots.[7] Robson noted the plant's similarities toH. tosaense, but decided that minor differences in appearance and wide separation geographically warranted its inclusion as a separate species.[4] It is also closely related toH. momoseanum andH. yezoense.[5]
One origin of the genus nameHypericum is that it is derived from theGreek wordshyper (above) andeikon (picture), in reference to the tradition of hanging the plant over religiousicons in one's home.[8] Thespecific epithet is made up of the combination ofiwate, for the species' habitat in theIwate Prefecture, andlittorale, which derives from the Latin wordlitoralis and means "littoral" or "coastal".[9] Its Japanese name isシオカゼオトギリ, transliterated asshio kaze otogiri.[10][11]シオカゼ (shio kaze) can be translated as "sea breeze" andオトギリ(otogiri) refers to the genusHypericum, giving the common name "sea breeze St. John's wort".[12][13]
Hypericum iwatelittorale is found intemperate coastal regions of theIwate Prefecture inHonshu, Japan.[1] Theholotype of the species was collected on the Omoe Peninsula inShimohei District, and is now held at the JapaneseNational Museum of Nature and Science.[14]
The conservation status ofH. iwatelittorale was first surveyed by the JapaneseMinistry of the Environment in 2012, but it was assessed asdata deficient.[10] The species is also considered data deficient by the Global Red List of Japanese Threatened Plants.[15] The local Iwate Red Data Book evaluated threats to the species caused by the2011 Tōhoku earthquake, and concluded thathabitat loss due to natural disasters or road construction were the greatest risks.[16] As of the 2020 Red Data assessment, it was still classified as having a "lack of information".[11]